Here's an chain of reasoning that I think is in Aristotle. Write out what you think are the missing bits in the reasoning. (Note that it doesn't fit our definition of an argument, as it involves a sequence of inferences not just one.)

1. Assume that being a good citizen = being a good person.
2. Assume also that states differ from each other.
3. From (2) it follows that there are cities x and y such that: being a good citizen of x being a good citizen of y.
4. From (1) and (3) it follows that being a good citizen of x = being a good person.
5. From (1) and (3) it also follows that ___________________.
6. From __________ it follows that being a good citizen of x = being a good citizen ofy.
7. But that contradicts (3). So, one of our starting assumptions must be ___________.